Mobile device cameras have come a long way in the last 10 years. Originally, a camera’s most important spec was the number of megapixels. Now, people who want to shoot high-quality photos also want control over the f-stop, ISO and shutter speed.

Being able to control these, and understanding what each does, allows the operator to create first-rate images in any setting.

Some newer mobile devices offer a “pro” set of controls that exposes those settings. Samsung’s Galaxy S7 Edge allows the user to control many settings beyond just focus and lighting. Today, we’ll discuss f-stop, shutter speed and ISO, and how to control them to produce images you want.


A camera’s f-stop allows you to control how much light enters the lens. If you’re in a very bright setting, you want to reduce that amount. The higher the number, the less light.

f-stop illustration

This is also called the aperture. While it primarily controls the amount of light in the lens, it will also affect depth of field. The more open the f-stop, the shallower your depth of field.


This is a measure of how far the shutter stays open when you’re shooting a photo. Instead of how much light you let in (as with the f-stop), this controls the amount of time that the light is admitted, generally measured in seconds.

If you want a sharp image, make sure that your f-stop setting allows enough light and keep your shutter speed very brief. The longer it’s open, the more movement is captured. Look at this example of a windmill shot, left to right, with short, medium and longer shutter speeds:

Effect of shutter speed

Effect of shutter speed

Obviously, the short shutter speed produces a sharper image, and the longer one is much blurrier and depicts more movement.

If you have a Google Nexus 5, you can download A Better Camera on the Google Play store site. It allows taking more professional-looking photos on your mobile device.


The ISO measures the sensitivity of the camera’s sensor and often affects the quality of the image. The lower the ISO number, the less sensitive it is to light. A higher ISO number increases your camera’s sensitivity.

If you’re in a well-lighted environment, use the lowest ISO available. This prevents unnecessary graininess in the image. As available light decreases, increase the ISO, making the light receiver more sensitive to light that you admit through the f-stop and shutter speed.

To control the ISO on your Android device, download Open Camera. That will also control several other features, including stabilization, exposure time and manual focus distance.

In the example below, the lower the ISO, the less sharp the image. The higher the ISO, the clearer the image.

Shutterspeed © Patrick Mayon

While it may be difficult to tell in just one of these images, putting them side by side highlights the noticeable difference between lower and higher ISOs.

Typically, more controls are built into Android native cameras than into their iOS counterparts. However, you can find many apps that produce more control while using either type of phone. Download our free list of recommended apps here.